Summary: What exactly is measured
in high pressure melting experiments?
V. Sorkin, E. Polturak and Joan Adler
Department of Physics
Technion - Israel Institute of Technology.
1
Introduction & Objectives
Phase diagrams of materials at high pressures are of great interest due to
their importance for geology and astrophysics [1]. One way to determine the
region of phase diagram is through observations of melting at high pressures.
Various techniques are employed in these studies in the laboratory including
the diamond anvil cell (DAC) [2] and shock waves [3].
Inside a DAC, the sample is surrounded by a pressure transmitting medium.
In shock-wave experiments the molten region inside the sample is bordered by
cold regions. In both cases, the sample has no free surface. At zero pressure,
the mechanism of melting depends on whether the sample does or does not have
a free surface [4]. We examine the question of how the boundary conditions
affect the melting transition at high pressures.
2
Models & Method